Spirochetes were isolated from the feces of 11 homosexual males who had diarrhea. The anaerobic organisms were isolated from a selective medium that consisted of Trypticase soy agar supplemented with either 5 % horse or human blood, 400 jig of spectinomycin per ml, and 5 jig of polymyxin B per ml. Nonselective media that permitted good growth of these fastidious organisms were developed, and selected biochemical tests were performed. The tests included carbohydrate utilization, detection of certain enzymes, and determination of volatile fatty-acid end products of metabolism. Two growth patterns were noted on solid media, a haze of growth and production of small colonies. Based on the results of biochemical tests, patterns of preformed enzymes, and volatile fatty-acid production, we believe that the 11 isolates represent a heterogeneous group of spirochetes. The data suggest that the human colon may harbor unique strains of cultivable spirochetes; additional study of the taxonomy of the organisms and assessment of their virulence for humans are needed. An association between spirochetes and the human intestinal mucosa was first documented by Escherich in the late 19th century (7, 8). Since that time, scientific interest in this association, often referred to as intestinal spirochetosis, has
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.